The present invention relates to a cordless telephone system.
U.S. Pat. No. 4,291,197 discloses an example of a cordless telephone system. The system comprises a radiophone including a radio receiver of a reception frequency f1 and a radio transmitter of a transmission frequency f2, and a radio station wired to a communication line. The radio station has a radio transmitter/receiver of a transmission frequency f1 and a reception frequency f2. The radio station and the radiophone perform communication in a full duplex manner.
In a conventional cordless telephone system, basically only a single radiophone is connected to a single telephone line.
When a plurality of radiophones are used, it is convenient if communication can be performed between radiophones. However, since the respective radiophones have the same transmission frequency f2 and reception frequency f1, they cannot communicate with each other.